Canon EOS-1D X Mark III DSLR Camera (Body Only) - Manual (Page 490)

3.
Select the image to be rated.
Turn the < > dial to select the image to be rated.
4.
Rate the image.
Press < >, and a blue highlight frame will appear as shown in the
screen shown above.
Turn the < > dial to select a rating mark, then press < >.
When you append a rating mark to the image, the number beside the
set rating will increase by one.
To rate another image, repeat steps 3 and 4.
Note
By pressing the < / > button, you can also rate images during playback ( ).
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